Conventionally, a magnetic tape serving as a magnetic recording medium is widely used as a recording medium used for other record reproducing devices such as an audio device and a video device. Generally various films, such as a magnetic tape, a movie film, and an X ray film, are wound on the tape reel as shown in FIGS. 1 and 2 to be held. FIG. 1 is a perspective view showing one example of the tape reel. Also, FIG. 2 is a sectional view taken along the line A—A in FIG. 1.
As shown in FIG. 1, a tape reel 40 is constituted including a cylindrical hub 41 having tape T wound thereon on outer peripheral surface, and one pair of disk-shaped lower flange 42 and upper flange 43 fixed to a lower end 41a and an upper end 41b of the hub 41. In addition, the upper flange 43 is fabricated from a transparent material in many cases so that a winding appearance and a winding volumes of the tape T wound on the hub 41 can be checked visibly.
As shown in FIG. 2, the lower flange 42 and the upper flange 43 are brought into contact with tape edge E1 of upper side and tape edge E2 of lower side of the tape T wound on the hub 41. And the position of the tape edge E1 and or E2 is controlled, to thereby control the movement of the tape in a width direction of the tape T. In FIG. 2, an inner surface 42a of the lower flange 42 is brought into contact with the tape edge E2 of the lower side of the tape T, and control the position of the tape edge E2 of the lower side, to thereby control the movement of the tape T in the width direction. This enables a stable traveling of the tape T, and consequently the record reproducing feature of the tape T can be maintained good.
In addition, inner surface 42a of the lower flange 42, and inner surface 43a of the upper flange are formed in inclined surfaces which are inclined from inner peripheral side (left-hand side in the drawing), at a predetermined angle toward the outer surfaces 42b and 43b of the flanges 42 and 43. Thus, the inner surfaces 42a and 43a of the flanges 42 and 43 are formed in inclined surfaces, to thereby make it easy for the tape T wound on outer periphery of the hub 41 to come out from between flanges 42 and 43, when feeding out the tape T from the tape reel 40. Also, when un-winding the tape T on the tape reel 40, the tape T easily enters into between flanges 42 and 43. This allows the tape T to travel stably when feeding out the tape T from the tape reel 40, and taking up the tape T on the tape reel 40.
As shown in FIG. 3, the tape reel 40 is fabricated using resin as a material in such a manner that the upper flange 43 fabricated separately is bonded to upper end 41b of the hub 41 integrally fabricated with the lower flange 42, by welding or adhesives. FIG. 3 shows the manufacturing process of the tape reel 40 in which the upper flange 43 is bonded to the upper end 41b of the hub 41 integrally fabricated with the lower flange 42, to thereby manufacture the tape reel 40. However, in manufacturing the tape reel 40, the upper flange 43 and the hub 41 are integrally fabricated with the upper flange 43 beforehand, then the lower flange 42 may be bonded to the lower edge 41b of the hub 41.
By the way, in recent years, higher recording density and higher speed of a tape are progressing, therefore stable traveling of the tape is further required. In the tape reel 40 as shown in FIG. 1 and FIG. 2, high dimension accuracy of the position of the flanges 42 and 43, distance between the flanges 42 and 43, and inclined angles of the inner surfaces 42a and 43a of the flanges 42 and 43 is required. Therefore, after manufacturing the tape reel 40, it is necessary to inspect the dimension accuracy of the the position of flanges 42 and 43, the distance between flanges 42 and 43, and the inclined angles of the inner surfaces 42a and 43a of the flanges 42 and 43 respectively.
Also, generally, in case that the flanges are welded to the hub, to thereby form a reel, or two sheets of disks are mutually laminated, to thereby form one sheet of disk, the hub and the disk of positioning side are engaged with guide pins for positioning. In this state, the flanges and disks are welded or bonded. However, in order to improve the accuracy of the positioning by tight engagement of the hub and the disk, a problem is involved therein in such a way that it is easily damaged by an unreasonable handling. For this reason, a positioning device that performs positioning by grasping the flange by a clamp is proposed. (For example see JP-A-06-231452).
However, in the conventional needle contact type measuring method, error of μm order is generated by slight contact pressure of the probe needle, thereby involving a problem that the size of the μm order of an object to be measured cannot be measured. Moreover, more problems are involved therein in such a way that an object to be measured is damaged by the probe which is contacted with the object to be measured one by one, or time required for measurement is longer compared with an optical measuring method that measures in an un-contacting state. In addition, when a miniaturized tape reel is inspected in order to hold a tape with narrow width, distance between flanges becomes short. Thereby it becomes difficult to insert the probe between flanges.
On the other hand, in the conventional optical measuring method, inspection light is irradiated on the surface of a target object, so as to receive the reflected light. Therefore, there is raised a problem that the position of the flanges 42, 43, the distance between the flanges 42, 43, and the inclined angle of the inner surfaces 42a, 43a cannot be measured.
Here, a method for inserting a reflective sensor or a mirror between the flanges 42 and 43 is conceivable, however involving a problem that the structure of the inspection device is complicated. Especially, the dimension accuracy of the position of the flanges 42, 43, the distance between the flanges 42, 43, and the inclined angles of the inner surfaces 42a, 43a are inspected immediately after manufacture of the tape reel 40, therefore the inspection device is required to be arranged on the manufacturing process of the tape reel 40. However, if the reflective sensor or the mirror is interposed between the flanges 42 and 43, there is posed problems such as, (1) the constitution of the inspection device is complicated, therefore it becomes difficult to arrange the inspection device on the manufacturing process of the tape reel 40; (2) there is a possibility that the flange 42, and the reflective type sensor and mirror which are interposed between the flanges 42 and 43, may collide with the upper flange 42 or the lower flange 43, and may be damaged; (3) when the upper flange 43 is fabricated from a transparent material, the inspection light irradiated onto the inner surface 43a of the upper flange 43 penetrates the upper flange 43 which is transparent material, and cannot receive a reflected light, or it is reflected by the inner surface 43a of the upper flange 43 which is a transparent material, involving an error.
Moreover, the positioning device that performs positioning by grasping the flange by the clamp poses further problems that the number of parts is increased as a mechanism is complicated, raising a failure ratio and price.
Also, when inspecting the tape reel, the positioning of the position of the flanges of the tape reel must be performed accurately, so that a commodity value of a tape may not fall. Therefore, it is required that the accurate positioning of the position of the flanges is improved even more.